Age UK owes me £760 but I can’t get it back

I want a hearing aid deposit returned, but the charity’s commercial arm just won’t listenBack in April last year I tried a hearing aid supplied by Age UK’s commercial arm, paying a deposit of £760 against a total of £3,000. When it became clear it was not fit for my purpose, I returned it. I have been trying, for the last few months, to get my deposit back. I have been repeatedly told it will be paid in three or four weeks, but nothing happens.RW, Cambridge Continue